Sensing device, system and method for pump

Abstract

A sensing device for a centrifugal slurry pump, the centrifugal slurry pump having an impeller rotating about an axis, the centrifugal slurry pump comprising a side bushing and a main bushing housed in a casing of the pump, the sensing device comprising: a main body portion arranged to pass through the casing, wherein the main body portion comprises a sensor biased toward contact with the side bushing or the main bushing of the pump.

Description

Technical Field

[0001] The present invention relates generally to an apparatus, system and method for a pump, and more particularly to an apparatus, system and method suitable for detecting wear in a pump. Background Art

[0002] A slurry pump is a pump designed to pump a slurry, which is a liquid containing solid particles. Considering the various types of slurries that may vary in the concentration of solid particles, the size of the solid particles, the shape of the solid particles, and the composition of the solution, the design and construction may vary. An example of a slurry pump is a centrifugal pump.

[0003] Due to the abrasive nature of the media being pumped, slurry pumps experience very high wear rates on their internal components, such as the main bushing that houses the impeller and the side bushings located on either side of the main bushing. The side bushings may include a front bushing located on the inlet side of the impeller. Alternatively, the side bushings may include a rear bushing located on the opposite side of the impeller. In particular, the front bushing (also called the throat bushing) and the main bushing (also called the volute) are subject to a lot of wear.

[0004] The performance and wear life of a centrifugal pump is directly related to the clearance located between the rotating impeller and the front side bushing. This clearance is particularly important for slurry pumps because a larger clearance results in a higher recirculation flow in the high pressure area of ​​the pump casing. This recirculation flow reduces pump efficiency and also increases the wear rate on the pump impeller and front side bushing. Over time, as the clearance widens, pump performance decreases more and the wear rate increases. Some conventional side bushings can be axially adjusted to reduce the clearance. However, such an adjustment does not reduce localized wear and any localized wear pits will grow larger over time.

[0005] Furthermore, it is important for operators to know the thickness of the front, rear and main side bushings to perform effective maintenance. Such information would inform the operator of a slurry pump of the best time to replace the bushings, as replacing them too early is economically undesirable, while replacing them too late carries the risk of bushing failure and damage to the impeller, casing and other components. However, accurately determining the thickness of the various bushings is challenging due to their location within the thick casing of the pump. As a result, it is common to disassemble the pump and visually inspect for wear, a time-consuming and expensive task.

[0006] In the past, ultrasonic sensors have been mounted on the exterior of the pump housing, using magnets or other such devices to attach the ultrasonic sensing device to the pump. Such devices can be placed around various locations on the exterior of the pump and wired together to communicate with each other. However, such solutions require the thickness of internal components to be determined through different surfaces, such as a thick outer casing. The outer casing is designed to accommodate the high pressures generated during pump operation, but the thickness of the casing can reduce the accuracy of external readings. In addition, other problems are encountered when measuring the thickness of the front side bushing that is axially adjustable relative to the main bushing.

[0007] Preferred embodiments of the present invention seek to address one or more of these disadvantages, and / or at least provide the public with a useful alternative.

[0008] Reference in this specification to any previous publication (or information derived from a previous publication) or any known matter is not and should not be taken as an acknowledgement or approval or any form of suggestion that the previous publication (or information derived from a previous publication) or known matter constitutes common general knowledge in the field to which this specification relates. Summary of the invention

[0009] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0010] In a first aspect, there is provided, by way of example only, a sensing device for a centrifugal slurry pump having an impeller rotating about an axis, the centrifugal slurry pump comprising a side bushing and a main bushing housed within a casing of the pump, the sensing device comprising: a main body portion arranged to pass through the casing, wherein the main body portion includes a sensor biased towards contact with the side bushing or the main bushing of the pump.

[0011] In another exemplary embodiment, the side bushing is a front bushing, the front bushing comprising a front face and a rear face, the front face being arranged to face the impeller housed in the main bushing, and the rear face being arranged to face the casing, wherein the front bushing is arranged to be axially adjustable relative to the main bushing, and the sensor is arranged to remain biased toward the front bushing and in contact with the front bushing when the front bushing is axially adjusted relative to the main bushing of the pump.

[0012] According to a further optional aspect provided by way of example only, the sensor senses a distance between the front face and the rear face to provide at least one thickness reading of the side bushing or the main bushing.

[0013] In another embodiment, the at least one thickness reading includes a first thickness reading and a second thickness reading, wherein the first thickness reading and the second thickness reading are separated by a period of use of the pump.

[0014] In yet another specific but non-limiting form, the body portion includes a head portion, and the head portion includes a communication module connected to the sensor.

[0015] In another non-limiting embodiment, the head portion is arranged to be located outside a surface of the housing.

[0016] In another exemplary embodiment, the communication module transmits each of the first thickness reading and the second thickness reading from the sensor to a computing device.

[0017] In yet another example, the computing device compares the first thickness reading and the second thickness reading to determine a change in thickness of the main bushing or the side bushing over a period of use.

[0018] According to another optional aspect, a user of the computing device axially adjusts the position of the front bushing relative to the main bushing according to the thickness variation of the front bushing so that the distance between the front bushing and the impeller received in the main bushing remains constant.

[0019] In another embodiment, the body portion includes an elongated tubular member, wherein the elongated tubular member is slidingly received within the head portion.

[0020] In another non-limiting embodiment, the first end of the elongated tubular member includes a biasing mechanism that biases the elongated tubular member toward a main bushing or a side bushing of the pump.

[0021] In yet another non-limiting example, the biasing mechanism is a spring.

[0022] According to a further optional aspect, the second end of the elongated tubular member portion includes the sensor.

[0023] In an embodiment, the body portion comprises a connecting portion arranged to be connected to the housing.

[0024] In yet another exemplary embodiment, the body portion is removably connected to the connecting portion such that the sensing device passes through a housing of the pump.

[0025] According to another optional aspect, the main body portion is cylindrical.

[0026] In another embodiment, the head portion further comprises at least one power source.

[0027] In another embodiment, the at least one power source is connected to the communication module and powers the operation of the sensor.

[0028] In yet another exemplary embodiment, the sensing device comprises a wired connection connecting the communication module to the ultrasound device.

[0029] According to a further optional aspect, the wired connection is arranged to enable relative movement of the elongated tubular member with respect to the head portion.

[0030] In another embodiment, the wired connection is an expandable and retractable coil of insulated wire.

[0031] In yet another non-limiting embodiment, the at least one power source is a lithium battery.

[0032] In another embodiment, the sensor is an ultrasonic sensor.

[0033] In another embodiment, the ultrasonic sensor is an ultrasonic transducer.

[0034] According to a further optional aspect, the ultrasonic transducer is a piezoelectric transducer.

[0035] In yet another embodiment, the side bushing is a rear bushing, wherein the sensor is arranged to remain in contact with the rear bushing of the pump.

[0036] In a second aspect, a system for detecting wear in a centrifugal slurry pump is provided, the centrifugal slurry pump having a side bushing and a main bushing housed in a housing, the system comprising a sensing device arranged to pass through the housing, wherein the sensing device comprises a sensor biased toward and in contact with the side bushing or the main bushing of the pump.

[0037] According to another optional aspect, the sensor detects a first thickness reading and a second thickness reading of the side bushing or the main bushing.

[0038] In yet another embodiment, the system further comprises a computing device in communication with the sensing device, the computing device being arranged to receive the first thickness reading and the second thickness reading from the sensing device.

[0039] In yet another exemplary embodiment, the computing device uses the first thickness reading and the second thickness reading to determine a thickness change of the side bushing or the main bushing.

[0040] In yet another non-limiting example, the side bushing is a front bushing arranged to be axially adjustable relative to the main bushing, wherein a user axially adjusts the front bushing relative to the main bushing according to a thickness variation of the front bushing.

[0041] In a third aspect, a method for detecting wear in a centrifugal slurry pump is provided, the centrifugal slurry pump having a side bushing and a main bushing housed in a housing, the method comprising the following steps: arranging a sensing device to pass through a surface of the housing, the sensing device comprising a sensor; arranging the sensing device relative to the pump so that the sensor is biased toward and in contact with the side bushing or the main bushing; transmitting a first thickness reading and a second thickness reading of the side bushing or the main bushing from the sensing device to a computing device, and determining a thickness change of the side bushing due to wear using the computing device.

[0042] According to yet another example form, there is provided an apparatus for a centrifugal slurry pump having a side liner and a main liner, the side liner being arranged to be axially adjustable relative to the main liner, the apparatus comprising: an ultrasonic sensor adapted to be biased toward contact with the side liner of the pump such that the ultrasonic sensor remains in contact with the side liner to determine at least one thickness reading of the side liner.

[0043] In a fourth aspect, a sensing device for a sleeveless centrifugal slurry pump is provided, the sleeveless centrifugal slurry pump having an impeller rotating around an axis, the centrifugal slurry pump comprising a casing of the pump, the casing comprising an inner surface and an outer surface, the sensing device comprising; a main body portion, the main body portion being arranged to engage with a bracket connected to the outer surface, wherein the main body portion includes a sensor biased toward contact with the outer surface of the pump.

[0044] In an embodiment, the sensor senses a distance between the outer surface and the inner surface to provide at least one thickness reading for a casing of the linerless centrifugal slurry pump.

[0045] In another embodiment, the sensing device is connected to the housing of the linerless centrifugal slurry pump via a bracket, the bracket being arranged to be connected to at least one non-wearing surface provided on the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Exemplary embodiments will become apparent from the following description of at least one non-limiting embodiment, given by way of example only, in conjunction with the accompanying drawings.

[0047] Figure 1 A cross-sectional view of a sensing device according to an embodiment of the present invention is shown.

[0048] Figure 2 A bottom perspective view of an exemplary main bushing is shown in accordance with an embodiment of the present invention.

[0049] Figure 3A side view of an exemplary main bushing is shown in accordance with an embodiment of the present invention.

[0050] Figure 4 A side view of an exemplary front bushing according to an embodiment of the present invention is shown.

[0051] Figure 5 A perspective view of an exemplary front bushing according to an embodiment of the present invention is shown.

[0052] Figure 6 A perspective cross-sectional view of a sensing device according to an embodiment of the present invention is shown.

[0053] Figure 7 An example user interface for a sensing device according to an embodiment of the present invention is shown.

[0054] Figure 8 , Figure 8.1 and Figure 8.2 A side view, a bottom perspective view, and a top perspective view of a sensing device according to an embodiment of the present invention are respectively shown.

[0055] Fig. 9 A top perspective exploded view of a sensing device according to an embodiment of the present invention is shown.

[0056] Fig.10 A top perspective exploded cross-sectional view of a sensing device according to an embodiment of the present invention is shown.

[0057] Fig.11 A side cross-sectional view of a sensing device according to an embodiment of the present invention is shown.

[0058] Fig.12 A side cross-sectional view of a sensing device according to an embodiment of the present invention is shown.

[0059] Fig.13 A perspective exploded view of a sensing device according to an embodiment of the present invention is shown.

[0060] Fig.14 A bottom perspective view of an exemplary housing for a linerless pump according to an alternative embodiment of the present invention is shown.

[0061] Fig.15 A right side view of an exemplary housing of a linerless pump according to an alternative embodiment of the present invention is shown.

[0062] Fig.16 An exploded perspective view of an example of a sensing device according to an embodiment of the present invention is shown.

[0063] Fig.17 A perspective view showing an example of a sensing device according to an embodiment of the present invention.

[0064] Fig.18 A partial view of a perspective view of a sensing device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0065] The following modes, given by way of example only, are described in order to provide a more precise understanding of one or more embodiments.In the drawings, the same reference numerals are used to identify the same bushings throughout the figures.

[0066] General Reference Figures 1 to 5 The present invention is described with respect to a centrifugal slurry pump, hereinafter referred to as a "pump". The pump may be sleeved or sleeveless. That is, sleeved pumps include internal wear sleeves, while sleeveless pumps do not. These wear sleeves are described in more detail below.

[0067] A general description of the liner pump 102 is provided as follows. The pump 102 can include a housing 104 that provides an outer casing for the internal components of the pump 102. The housing 104 can be formed of cast iron or ductile cast iron. The pump 102 can be supported by a base or a foundation attached to the housing 104. The housing 104 can be formed by two side shell portions or halves (sometimes also referred to as a frame plate and a cover plate) that are coupled together around the perimeter of the two side shell portions.

[0068] The pump 102 is formed with an inlet aperture and a discharge outlet aperture. In use, such as in a processing plant, the pump 102 is connected to the inlet aperture and the outlet aperture by a pipeline, such as to facilitate pumping of a mineral slurry.

[0069] The pump 102 may include a side bushing and a main bushing housed within a housing 104 of the pump 102. More specifically, the housing 104 houses a main bushing (or volute) and two side bushings. An example of a main bushing 108 is shown in FIG. Figure 2 and 3 The main bushing 108 also defines a pump chamber 110 in which an impeller (not shown) is positioned for rotation. The impeller is attached to a drive shaft rotated by a motor, wherein the drive shaft drives the impeller to rotate within the pump chamber 110 about an axis.

[0070] The housing 104 also houses two side bushings, the first of which is a rear bushing (also referred to as a rear bushing) that is located closer to the rear end of the pump 102 (i.e., closest to the base or seat). The other side bushing is a front bushing 106 (also referred to as a front bushing or throat bushing) and is located closer to the front end of the pump 102, adjacent the inlet hole or suction side of the pump 102. Thus, the front bushing 106 on the suction side of the pump 102 is provided with an opening 112 to accommodate the inlet hole. An example of the front bushing 106 is shown in FIG. Figure 4 and 5 The front side liner 106 may further include a front face 114 and a rear face 116 , the front face 114 being arranged to face the impeller accommodated in the main liner 108 , and the rear face 116 being arranged to face the casing 104 .

[0071] refer to Figure 6 , an embodiment of a sensing device 100 is provided. The sensing device 100 can be provided to a pump 102. The sensing device 100 can include a body portion 118 arranged to pass through a housing 106. In an embodiment, the body portion 118 includes a sensor 120, which can be arranged to contact a side bushing 106 or a main bushing 108 of the pump 102. In another embodiment, the sensor 120 can be arranged to be biased toward and contact the side bushing 106 or the main bushing 108 of the pump 102.

[0072] Reference again Figure 1 , an embodiment is provided in which the front bushing 106 can be arranged to be axially adjustable relative to the main bushing 108. In the context of this specification, the terms "axially adjustable" and "axial adjustment" mean that the front bushing 106 can translate or move along the rotation axis of the impeller. Thus, the front bushing 106 can be adjusted to maintain a constant distance between the front face 114 and the impeller contained in the main housing 108. In such an embodiment, the sensor 120 is arranged to be biased toward the front bushing 106 and maintain contact therewith when the front bushing 106 is axially adjusted relative to the main bushing 108 of the pump 102.

[0073] In an embodiment, the sensor 120 is an ultrasonic sensor that senses the distance between the front face 114 and the rear face 116 to provide at least one thickness reading of the front liner 106. In another embodiment, the sensor 120 is an ultrasonic sensor that senses the distance between an inner surface 122 of the main liner 108 (i.e., the surface of the pumping chamber facing the impeller) and an outer surface 124 of the main liner (i.e., the surface facing or in contact with the housing 104) to provide at least one thickness reading of the main liner 108.

[0074] Alternatively, the sensor 120 can be an ultrasonic sensor for sensing the thickness of a side bushing, wherein the side bushing is a rear bushing arranged to be located between the impeller and the motor. That is, the rear bushing is located on the side of the impeller opposite to the front bushing. In all such embodiments, the sensor 120 is arranged to contact the bushing and biased toward the bushing. In the following description, the term "bushing" can interchangeably refer to any one of the front bushing, main bushing, or rear bushing of the pump 102. In an embodiment, the bushing can be made of a wear-resistant material, such as, but not limited to, a high chrome alloy material. Alternatively, the bushing can be made of a wear-resistant elastomeric material.

[0075] The sensor 120 may be an ultrasonic sensor, such as an ultrasonic transducer, which may include a piezoelectric transducer or a capacitive transducer. For example, the transducer may be a single element, longitudinal wave transducer for direct contact. Alternatively, the transducer may be a dual element transducer, which includes two crystal elements housed in a single housing, the crystals being separated by an acoustic barrier. One element transmits a longitudinal wave, and the other element acts as a receiver.

[0076] In alternative embodiments, other types of ultrasonic sensors may be used, such as a replaceable delay line transducer, which is a heavily damped single element used with a replaceable delay line, or an immersion transducer, which is a single element, longitudinal wave transducer with a quarter-wave layer matched to hydroacoustics. Thus, it is within the purview of those skilled in the art that other types of ultrasonic transducers may be used to perform the work of the present invention.

[0077] The sensor 120 may be arranged to generate ultrasonic pulses and transmit such pulses through the medium. The sensor 120 may also be arranged to receive echoes of such pulses while measuring the time interval between when they are received. Using this time interval, the thickness of the medium may be determined. For example, the sensor 120 may be arranged to emit ultrasonic pulses from the rear face 116 of the front side bushing 106 and receive reflected pulses reflected from the interface formed by the front face 114 of the front side bushing 106. Alternatively, the sensor 120 may also be arranged to emit ultrasonic pulses from the outer surface 124 of the main bushing 108 and measure the time interval until the sensor 120 receives the reflected pulses reflected from the interface formed by the inner surface 122 of the main bushing 108.

[0078] The sensor 120 can also measure the time interval between the pulse being transmitted and the reflected pulse being received. For example, this can be done by measuring the time interval between the transmission of the ultrasonic pulse through the liner and the first return echo of the pulse. A small offset value can be subtracted from the time interval to account for fixed instrument, cable and transducer wear plate delays. The thickness of the liner is determined using the measured time interval and the known speed of the acoustic pulse through the liner because the material of the liner and the speed of the ultrasonic pulse through the medium are known variables.

[0079] Alternatively, when referring to Figure 7 An example of a user interface is provided. The user interface is provided only to demonstrate a method by which the thickness of a liner can be determined by measuring the time interval between two consecutive back wall echoes. A back wall echo is an acoustic wave that bounces off the far side boundary of the liner. For example, Figure 7As shown in , for the sensor 120 in contact with the front side liner 106, the first interface echo 126 is a reflected acoustic signal from an ultrasonic pulse reflected from the back 116 of the front side liner 106. In addition, the first back wall echo 128 and the continuous second back wall echo 130 are reflected acoustic signals from the ultrasonic pulse reflected from the front 114 of the front side liner 106. The thickness of the liner between the back 116 and the front 114 can be determined by measuring the time period between the first back wall echo 128 and the second back wall echo 130. That is, the second back wall echo is a part of the ultrasonic pulse that has passed through the liner twice. As will be understood by those skilled in the art, this measurement can be performed multiple times for a single time point and combined to form a thickness reading. Combining multiple measurements into a single reading can improve the accuracy of the reading. For example, the thickness reading can include an average of approximately five to ten individual measurements.

[0080] In an embodiment, the sensor 120 may be arranged to sample at least one thickness reading within the same period of use of the pump 102, wherein the period of use is understood to refer to a discrete period of time during which the pump is operated. The sensor 120 may be arranged to sample at least one thickness reading, wherein the at least one thickness reading may include a first thickness reading and a second thickness reading. The first thickness reading and the second thickness reading are separated by the period of use of the pump 102. That is, the sensor 120 may be arranged to measure the thickness of the liner at two different points in time, wherein the pump 102 has been used and worn during the period between the two points in time.

[0081] In an embodiment, the sensing device 100 may include a polymer putty located between the sensor 120 and the bushing. The polymer putty may improve the efficiency of ultrasonic pulse transmission into the bushing and reduce the amplitude of the interface echo. The polymer putty may also provide a small adhesive effect that additionally increases the contact with the sensor 120 and the bushing.

[0082] In an embodiment, the body portion 118 includes a head portion 132, which includes a communication module 134 connected to the sensor 120. The communication module 134 can be arranged to transmit data collected from the sensor 120 to a computing device. The data can represent the time period between various ultrasonic pulses and reflections as described above. The term data refers to information transmitted by a signal. The data can contain multiple readings from a sensor at a single time point or across multiple time points.

[0083] In an embodiment, the communication module 134 may include a communication unit arranged to facilitate data communication between the sensing device 100 and a computing device. The computing device describes an independent computer under user control that is arranged to further analyze the data collected by the sensing device 100. The computing device may also be configured to store the data collected by the sensing device 100 and may include a server or other computer connected to the computing device via a network. Those skilled in the art will understand that the term computing device describes a wide range of computing devices, technologies, and architectures.

[0084] The communication unit may include a Bluetooth Low Energy (BLE) module and antenna for short and long range communication with a computing device or another wireless personal area network communication device or technology. The communication unit may be programmed to include communication cycles where the communication module 134 remains mostly inactive in a power save mode and will only transmit data to the computing device at optimal times for battery conservation, such as when a device capable of receiving data is detected to be within range. For example, when a user with a computing device, which may include a mobile device such as a smartphone, laptop, or tablet, comes within range of the communication unit.

[0085] The communication module 134 may also include a processor, such as a central processing unit (CPU) for processing data and other such operations. In addition, the communication module may include a memory module including volatile and non-volatile data storage devices so that data from the sensor 120 can be stored on the sensing device 100 for transmission to the computing device at a later time. The data storage device may be arranged to have the capacity to store hundreds or thousands of data sets collected by the sensor 120.

[0086] In an embodiment, the communication module 134 may be arranged to enable "remote processing" of data collected by the sensor 120. Remote processing in the context of this specification is understood to mean that the sensing device 100 is responsible for the collection and transmission of the data, while the computing device is responsible for processing, converting and contextualizing the data to form information. That is, the communication module 134 may be arranged to filter the analog data received from the sensor 120 to reduce or remove noise and artifacts and / or convert the analog data collected by the sensor 120 into digital data and transmit the digital data to the computing device. Once transmitted, the computing device may convert the data into a thickness reading. Alternatively, the sensor 120 may be arranged to filter the analog data received from the sensor 120 to reduce or remove noise and artifacts and / or convert the analog data into digital data, wherein the communication module 134 then transmits the digital data to the computing device for conversion into a thickness reading.

[0087] In an alternative embodiment, the communication module 134 may be arranged to provide "on-board" processing. On-board processing in the context of the specification is understood to mean that the sensing device 100 is responsible for collecting, processing, converting and contextualizing data to form information and transmitting the information to a computing device. For example, the CPU may be arranged to do one or more of the following: filter analog data received from the sensor 120 to reduce or remove noise and artifacts, convert analog data received from the sensor 120 to digital data, and use the digital data to determine at least one thickness reading. For example, the communication module 134 may be arranged to determine at least one thickness reading from the data received from the sensor 120 and transmit the at least one reading to a computing device.

[0088] In an embodiment, the computing device may be arranged to perform additional analysis or processing of the data. For example, the computing device may compare the first thickness reading and the second thickness reading to determine a change in thickness of the main bushing or the side bushing during use. In other words, the computing device may determine a change in bushing thickness by subtracting the first thickness reading from the second thickness reading. By knowing the change in bushing thickness, the user will be able to determine the degree of wear experienced by the internal components of the pump, which would otherwise be nearly impossible to determine without disassembling the pump.

[0089] In an embodiment, where the front bushing 106 may be arranged to be axially adjustable relative to the main bushing 108, the sensing device 100 enables a user to axially adjust the position of the front bushing 106 relative to the main bushing 108 according to a change in the thickness of the front bushing 106. In other words, the user changes the position of the front bushing 106 to keep the distance between the front bushing 106 and the impeller accommodated in the main bushing 108 constant.

[0090] The user can use the variation in bushing thickness to optimize the performance of the pump without having to disassemble the pump. That is, as the front face 114 of the front bushing 106 wears, the user axially adjusts the front bushing 106 by moving the front bushing 106 toward the impeller by the same distance as the thickness variation to ensure that the clearance between the impeller and the front bushing 106 remains within an optimal range. Otherwise, as the clearance increases, the increase in recirculation flow will reduce the efficiency of the pump and increase the wear rate on the pump impeller and the front bushing 106.

[0091] Reference now Figure 1 and Figures 8 to 11 , an embodiment is provided in which the main body portion 118 includes a head portion 132, wherein the head portion 132 includes a communication module 134 connected to the sensor 120.

[0092] The head portion 132 can be arranged to be aligned with a surface of the housing 104 or to be located externally thereto. Figure 1, the head portion 132 can be arranged to extend through the entire surface of the housing 104 and protrude beyond the outer surface. Alternatively, the head portion 132 can be arranged to be located in a recess formed in the outer surface of the housing 104 (not shown) so that the head portion 132 is flush with the outer surface of the housing 104. By positioning at least a portion of the head portion 132 outside the thick housing 104 or aligned with the housing 104, the sensor device 100 is able to wirelessly transmit the data collected by the sensor 120 to the computing device.

[0093] like Fig. 9 and 10 As shown in , the head portion 132 may include a cap 136 that is arranged to be removably connected to a base 138. The connection between the cap 136 and the base 138 provides a waterproof seal to prevent water and other contaminants, such as dirt, mud, or oil, from penetrating the head portion 132. The cap 136 can be connected to the base 138 by a threaded connection, which is facilitated by mating threads provided on the outer edge of the base 138 and the inner edge of the cap 136. Alternatively, the cap 136 can be connected to the base 138 by a snap-fit ​​connection. Such a connection method is provided as an example to demonstrate the working of the present invention. Therefore, in view of such changes, those skilled in the art will understand that other similar ways of removably connecting the cap 136 to the base 138 in a manner that facilitates a waterproof and dustproof housing will be understood to fall within the scope of the present invention.

[0094] The base 138 can be shaped to form a recess 140 that is arranged to receive a power supply housing 142 that is arranged to hold at least one power supply 144. The base 138 can also include a hollow housing 146 that has a first end and a second end. The first end 148 of the hollow housing 146 protrudes upward from the bottom of the base 138, wherein the first end 148 of the hollow housing 146 can be received in a recess formed in the center of the power supply housing 142. When the head portion 132 is assembled, the first end 148 is arranged adjacent to the at least one power supply 144 and the communication module 134. This arrangement Fig.11 146, wherein the first end 148 is adjacent to at least one power source 144 and the communication module 134. In addition, the first end 148 is formed with an opening 150 that can enter the interior 152 of the hollow housing 146. As shown, due to the rounded lip 154, the diameter of the opening 150 can be smaller than the diameter of the interior 152.

[0095] The hollow housing 146 can be arranged to extend beyond the base 138 of the head portion 132 such that the second end 155 of the hollow housing 146 is located distally relative to the at least one power source 144 and the communication module 134. The second end 155 of the hollow housing 146 is formed with an opening 156 having the same diameter as the diameter of the interior 152. That is, the opening 156 does not include a neck or lip.

[0096] In an embodiment, the body portion includes an elongated tubular member. The elongated tubular member may be arranged to be fixed or integrally formed with the head portion 132. Alternatively, Fig.12 An embodiment is provided in which the body portion 118 includes an elongated tubular member 158, wherein the elongated tubular member 158 is slidably received within the head portion 132. The opening 156 can be arranged to slidably receive the elongated tubular member 158, which will be referred to as the "tube member" hereinafter for convenience. The tube member 158 is hollow and sized to be freely slidable within the interior 152 of the hollow housing 146. The tube member 158 includes two ends, a first end 160 arranged to be received within the opening 156 and slidable within the interior 152. The outer diameter of the tube member 158 remains constant along its length. The second end 162 of the tube member 158 is arranged to hold the sensor 120. The first end 160 of the elongated tubular member 158 can include a biasing mechanism that biases the elongated tubular member 158 toward the main bushing 108 or the side bushing 106 of the pump 102 relative to the head portion 132.

[0097] The tubular member 158 also includes an elongated interior 164 defined and defined by an inner diameter. In an embodiment, the inner diameter along the length of the tubular member 158 can vary to define different sections of the elongated interior 164. For example, as Fig.12 As shown in FIG. 1 , the tube member 158 includes a first section 166, which is a portion of the elongated inner portion 164 and is arranged between the first end 160 of the elongated inner portion 164 and the second section 168. The inner diameter of the second section 168 is smaller than the diameter of the first section 166, so that the boundary of the first section 166 and the second section 168 forms a step 170.

[0098] The tube member 158 may further include a third section 172 disposed between the second section 168 and the second end 162 of the tube member 158. The inner diameter of the second section 168 is smaller than the diameter of the third section 172, such that the boundary of the second section 168 and the third section 172 forms a flange 174.

[0099] In another embodiment, an alternative arrangement is provided with an alternative elongated tubular member 176. The alternative tubular member 176 may include a first segment 178, which is a portion of the elongated inner portion 180 disposed between a first end 182 of the alternative tubular member 176 and a second segment 184 of the elongated inner portion 180. The inner diameter of the second segment 184 is smaller than the diameter of the first segment 178, such that a boundary of the first segment 178 and the second segment 184 forms a step 186.

[0100] The alternative tube member 176 may also include a third section 188 disposed between the second section 184 and a second end 190 of the alternative tube member 176. The inner diameter of the second section 184 is smaller than the diameter of the third section 188, such that the boundary of the second section 184 and the third section 188 forms a flange 192.

[0101] As can be seen from the tube member 158 and the alternative tube member 176, the tube members can include different variations and arrangements of arrangements, sizes, diameters, and lengths that can be used to accommodate different types of pumps and to accommodate different pump bushings. For example, the tube member 158 can be used with the front bushing 106, while the alternative tube member 176 can be used with the main bushing 108. Further variations of the tube member 158 can also exist to incorporate whether the bushing is axially adjustable within the pump 102.

[0102] In an embodiment, the first end of the tube member 158 includes a biasing mechanism that biases the tube member 158 toward the main bushing 108 or the side bushing 106 of the pump 102 relative to the head portion. For example, the tube member 158 includes a spring 194. The first end 196 of the spring 194 abuts the lip 154 ​​formed by the first end 148 of the hollow housing 146. The second end 198 of the spring 194 abuts the step 170 formed at the boundary of the first portion 166 and the second portion 168, and when so arranged, the spring 194 is in a compressed state. The sensor 120 is at least partially accommodated within the third section 172 at the second end 162 of the tube member 158. Thus, the biasing mechanism (in this case, the spring 194) biases the sensor 120 to contact the bushing of the pump 102 when in a compressed state. This in turn enables the sensor 120 to more accurately measure the thickness of the bushing of the pump 102 because the sensor 120 always remains in contact with the bushing due to the biasing force.

[0103] Furthermore, in embodiments where the bushing is the front bushing 106 and is axially adjustable, the biasing mechanism enables the sensor 120 to remain in contact with the front bushing 106 as the user axially adjusts the front bushing 106 relative to the main bushing 108. This in turn enables the sensor 120 to more accurately measure the thickness of the front bushing 106 of the pump 102 because the sensor 120 is always in contact with the front bushing 106 regardless of the axial position of the front bushing within the pump 102. This is particularly useful in Figure 1 , where the front bushing 106 has moved away from the housing 104 and this movement has caused a gap to form between these components, where the gap is broken by the expansion of the compression spring 194 which biases the sensor 120 into contact with the front bushing 106.

[0104] In an embodiment, the head portion 132 may also include at least one power source 144. For example, Fig.11As shown in FIG. 1 , the head portion 132 includes two power sources 144 disposed on opposite sides within the head portion 132. Such power sources may include, but are not limited to, lithium batteries, such as CR123A 3 volt lithium batteries. Alternatively, as Fig. 9 As shown in FIG, a symmetrical arrangement of four batteries is provided, but only three of these batteries are visible. In addition, another embodiment is provided in which the head portion 132 accommodates eight batteries. Therefore, those skilled in the art will understand that other arrangements, numbers of batteries, and types of batteries and power sources will be understood to be within the scope of the present invention.

[0105] In an embodiment, at least one power source 144 is connected to the communication module 134 and provides power for the operation of the sensor 120. In other words, the at least one power source is arranged to provide power to the sensor 120 via the communication module 134. The communication module 134 may include various circuit components to convert the voltage from the power source to the voltage required by the sensor to transmit the ultrasonic pulse. For example, the communication module may include a DC to DC boost converter or transformer to convert 3 volts from the power source to 400 volts as required by the sensor 120.

[0106] Thus, the connection between the communication module 134 and the sensor 120 is arranged to enable relative movement between the sensor 120 and the tube member 158 relative to the rest of the head portion 132. For example, the sensing device 100 includes a wired connection 200 that connects the communication module 134 to the sensor 120. The wired connection 200 is arranged to enable relative movement of the sensor 120 and the tube member 158 relative to the head portion 132. In an embodiment, the wired connection 200 is an expandable and contractible coil of insulated wire that is capable of transmitting electrical and data signals between the sensor 120 and the communication module 134. The wired connection 200 can be arranged to pass through the opening 156 and along the elongated interior 164. The wired connection 200 can form a helical coil along at least a portion or all of its length.

[0107] Reference now Fig.11 and 13 , an embodiment is provided in which the body portion 118 and / or the head portion 132 include a connection portion 204 that is arranged to be connected to the housing 104. The body portion 118 and / or the head portion 132 can be removably connected to the connection portion 204, which holds the body portion and / or the head portion to enable the sensing device 100 to pass through the housing 104 of the pump 102. The opening 202 can be formed to extend through the housing 104. The connection portion 204 can be fastened to the housing 104 by screws 206 or similar fastening devices that can achieve a secure and tight connection. The connection portion 204 can be arranged so that the opening 208 formed in the connection portion 204 is aligned with the opening 202 formed in the housing 104.

[0108] The main body portion 118 can be received and retained within the openings 202 and 208. The main body portion 118 and the connecting portion 204 can each include corresponding connecting cam surfaces that engage each other to removably connect the main body portion 118 to the connecting portion 204. For example, Fig.11 and 13 , the connecting portion 204 and the main body portion 118 may be connected together using a bayonet connection 210. However, those skilled in the art will appreciate that other similar mechanical means of removably and securely attaching the main body portion 118 and / or the head portion 132 to the connecting portion 204 may be available, thereby connecting the sensing device 100 to the pump 102.

[0109] refer to Figures 14 to 18 , an alternative embodiment for the sensing device 100 is provided for use with a linerless pump 212. The linerless pump 212 is a pump that does not include a separate liner that is subject to wear. Instead, the inner surface 218 of the housing 216 of the linerless pump 212 is subject to wear during the pumping process. The housing 216 can be formed of the same wear-resistant material as the liner described above. The linerless centrifugal slurry pump 212 includes an impeller that rotates about an axis. In addition, reference Fig.14 and 15 The linerless centrifugal slurry pump 212 includes a housing 216 including an inner surface 218 and an outer surface 220 .

[0110] In an embodiment, a sensing device 100 is provided for a linerless centrifugal slurry pump 212. The sensing device 100 may include a body portion 118 arranged to engage a bracket 214 connected to an outer surface 220, wherein the body portion 118 includes a sensor 120 that contacts or is biased toward contacting the outer surface 220 of the linerless centrifugal slurry pump 212.

[0111] In such an embodiment, the sensing device 100 may alternatively be configured such that the sensor 120 senses the distance between the outer surface 220 of the housing 216 and the inner surface 218 of the housing 216 to provide at least one thickness reading of the housing 216. That is, the sensor 120 may be arranged to transmit an ultrasonic pulse from the outer surface 220 of the housing 216 and measure the time interval until the pulse is reflected from the interface formed by the inner surface 218 of the housing 216.

[0112] In an embodiment, the sensing device 100 can be connected to the housing 216 of the linerless centrifugal slurry pump 212 via an elongated bracket 214. In an embodiment, the connecting portion 204 of the body 118 can be connected to the bracket 214 in a manner similar to how the connecting portion 204 is connected to the housing 202 of the liner pump 102 embodiment. In turn, the end of the bracket 214 is connected to the non-wearing surface 222 of the housing 216 of the linerless pump 212. Fig.16 As shown in , the bracket 214 is arranged to extend around or over a portion of the housing 216 and connect to the non-wearing surface 222 provided on either side of the linerless pump 212. In an example, the bracket can include a metal plate including an opening configured to receive and engage the connecting portion 204 via a mechanical fastener, a snap-fit ​​device, or a cam surface.

[0113] Connecting the sensing device 100 to the linerless pump 212 via the bracket 214 eliminates the requirement to drill into the housing 216. Drilling into the housing of the linerless pump 212 is difficult and expensive due to the wear-resistant material used for the housing 216. In addition, drilling into the housing 216 will also compromise the strength and thickness of the wear components, which may cause the linerless pump 212 to fail prematurely, which may be catastrophic.

[0114] refer to Fig.17 , multiple alternative embodiments are provided. In an embodiment, at least one sensing device 100 is connected to the linerless pump 212. In the example shown, the at least one sensing device 100 includes six sensing devices 100. The sensing devices 100 can be arranged in various arrangements to measure the thickness of the housing 216 of the linerless pump 212. The arrangement and relative positions of the sensing devices 100 shown are provided as examples only, and those skilled in the art will understand that such positions are non-limiting. In addition, those skilled in the art will also understand that the arrangement of multiple sensing devices 100 can also be used to measure the thickness of various bushings or various sections of bushings in the pump 102.

[0115] In an embodiment, five of the six sensing devices 100 are connected to the bracket 214 and one of the sensing devices 100 is directly connected to the non-wear surface 222. Thus, an embodiment is provided in which the non-wear surface 222 can be configured to receive and engage the connecting portion 204 via a mechanical fastener, a snap-fit ​​arrangement, or a cam surface.

[0116] In an embodiment, the sensing device 100 can be provided in a generally cylindrical shape. Thus, the head portion 132 and the tube member 156 can be cylindrical. That is, they have an approximately circular cross-sectional shape along a first axis and are elongated along another perpendicular axis. However, as will be appreciated by those skilled in the art, other shapes can be envisioned to accommodate changes in the position of sensors 120 of different sizes or shapes, bushings, or pumps. Therefore, it will be appreciated by those skilled in the art that changes in the size and general shape of the sensing device 100 are within the scope of the present invention.

[0117] Fig.18 Another embodiment is depicted in which the sensing device may be coupled to a connecting portion 204 which itself may be attached to a non-wearing surface of an outer surface 222 of a linerless pump casing.

[0118] refer to Figures 1 to 13 , an embodiment of a system for detecting wear in a centrifugal slurry pump 102 is provided. The pump 102 includes a side liner 106 and a main liner 108 housed within a housing 104. The system includes at least one sensing device 100 disposed through the housing 104, wherein the at least one sensing device 100 includes a sensor 120 biased toward contact with the side liner 106 or the main liner 108 of the pump 102. The at least one sensing device 100 can be arranged to detect a first thickness reading and a second thickness reading using the sensor 120. The first thickness reading and the second thickness reading can be with respect to the side liner 106 or the main liner 108 of the pump.

[0119] In an embodiment, the system may further include a computing device arranged to communicate with the at least one sensing device 100. The computing device may be arranged to receive the first thickness reading and the second thickness reading from the at least one sensing device 100. The computing device may then use the first thickness reading and the second thickness reading to determine a change in thickness of the side bushing 106 or the main bushing 108 due to wear occurring during operation of the pump 102.

[0120] In an embodiment, the side bushing 106 is a front bushing that is arranged to be axially adjustable relative to the main bushing 108. When determining the thickness variation of the front bushing 106, the user axially adjusts the front bushing 106 relative to the main bushing 108 according to the thickness variation of the front bushing 106. This enables the optimal distance between the front bushing 106 and the impeller to be maintained.

[0121] Again, reference Figures 1 to 13, an embodiment of a method for detecting wear in a centrifugal slurry pump is provided. The centrifugal slurry pump includes a side bushing 106 and a main bushing 108 housed within a housing 104 of the pump 102. The method includes the steps of first arranging at least one sensing device 100 through a surface of the housing 104. The at least one sensing device 100 includes a sensor 120 capable of detecting the thickness of the side bushing 106 or the main bushing 108. In addition, the at least one sensing device 100 is arranged so that the sensor 120 is biased toward contact with the side bushing 106 or the main bushing 108.

[0122] The method also includes the step of transmitting the first thickness reading and the second thickness reading of the side bushing or the main bushing to the computing device from the at least one sensing device 100. Once the first and second thickness readings have been transmitted to the computing device, the computing device uses the pump 102 to determine the change in thickness of the side bushing due to wear.

[0123] The sensing device referred to herein can be made of any material suitable for shaping, forming or assembling as described, such as a plastic material. The plastic material can have properties such as high mechanical strength and impact resistance, high glass transition temperature (Tg), UV resistance, water resistance, high dimensional stability and good chemical resistance. For example, the main body 118 can be made of a thermoplastic, such as acrylonitrile styrene acrylate (ASA) or other similar composite materials. The spring 194 can be made of a metal material or alloy that can effectively store mechanical energy. For example, the spring 198 can be made of stainless steel.

[0124] In the foregoing description of the preferred embodiments, specific terms are used for reasons of clarity. However, the present invention is not intended to be limited to the specific terms selected, and it should be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish similar technical goals. Terms such as "front" and "rear", "upper" and "lower" are used as convenient words to provide reference points and should not be interpreted as limiting terms.

[0125] It can also be said that the optional embodiments broadly include the parts, elements, steps and / or features referred to or indicated herein, either alone or in any combination of two or more of the parts, elements, steps and / or features, and where specific integers having known equivalents in the art relevant to the present invention are mentioned, such known equivalents are deemed to be incorporated herein as if set forth individually.

[0126] Although the preferred embodiments have been described in detail, it should be understood that modifications, changes, substitutions, or alterations will be apparent to those skilled in the art without departing from the scope of the invention.

[0127] Throughout this specification and the appended claims, unless the context requires otherwise, the word "comprise" and variations such as "comprised", "comprises" or "comprising", will be understood to imply the inclusion of stated integers or steps or groups of integers or steps but not the exclusion of any other integers or steps or groups of integers or steps.

[0128] As used herein, a, an, the, at least one, and one or more are used interchangeably and refer to one or more (i.e., at least one) of the grammatical objects. For example, "an element" means one element, at least one element, or one or more elements.

[0129] In the context of this specification, the term "about" is understood to refer to a numerical range that one skilled in the art considers equivalent to the recited value in the context of achieving the same function or result.

[0130] advantage

[0131] The embodiments described herein provide a novel means for a user to determine the thickness of a liner within a pump at various points along the liner. Furthermore, the described embodiments enable a user to determine the thickness of the liner with greater accuracy than any current technology. In particular, the arrangement of the sensor biased toward the main liner, side liner, and / or housing provides little to no air gap between the sensor and the main liner, side liner, and / or housing, which increases the accuracy of the readings.

[0132] The devices, systems, and methods described herein provide users with information that allows them to identify the optimal time to replace or repair liners. Replacing or repairing liners at the optimal time avoids the economic cost of replacing liners too early. Moreover, replacing or repairing liners before they are excessively worn can also reduce the risk of liners failing and damaging impellers, casings, and other components. In essence, the described embodiments provide operators and users with accurate and relevant information to eliminate the "guess work" regarding optimizing maintenance on a pump. Furthermore, this information can be obtained without having to open the pump and visually inspect the liners, which is a time-consuming and costly process.

[0133] Furthermore, these embodiments enable determination of the thickness of an axially adjustable front bushing, for which no current solution is able to accommodate this axial adjustment when determining the thickness of the front bushing.

[0134] Furthermore, embodiments describe a sensing device that can be retrofitted to existing pumps without compromising the integrity of the housing when operating under high pressure conditions.

[0135] Furthermore, the described embodiments enable wireless communication of information about the thickness to the user in a fast and efficient manner.Furthermore, the interchangeability of components enables easy and cost-effective replacement of the sensing device and modification of the sensing device to accommodate different pumps.

[0136] Furthermore, the described sensing devices may be capable of running various types of software that would enable the sensing devices to communicate with any "smart" device with the appropriate software installed, as described above. Thus, the broad application of the devices, systems, and methods would not be limited to transmitting data to any particular device or platform.

[0137] In another advantageous aspect, the described embodiments provide a device that, once initially installed, allows for easy and tool-free removal and attachment of the sensing device. Furthermore, the easily removable design of the sensing device improves the serviceability and maintainability of the pump.

[0138] Furthermore, once sufficient thickness readings and such data have been collected from the sensing device, further analysis of the date by the computing device described above may include predicting when the pump will require maintenance with greater accuracy than currently available methods.

Claims

1. A sensing device for a centrifugal slurry pump, the centrifugal slurry pump having an impeller rotating about an axis, the centrifugal slurry pump comprising a front bushing and a main bushing housed in a housing of the pump, the front bushing comprising a front face and a rear face, the front face being arranged to face the impeller housed in the main bushing, and the rear face being arranged to face the housing, the sensing device comprising: A main body portion is arranged to pass through the housing, wherein the main body portion includes a sensor in contact with the front bushing, wherein the sensor is biased toward contact with the front bushing, the front bushing is arranged to be axially adjustable relative to the main bushing, and the sensor is arranged to remain biased toward and in contact with the front bushing when the front bushing is axially adjusted relative to the main bushing, thereby enabling the sensor to detect the thickness of the front bushing.

2. The sensing device of claim 1, wherein the sensor senses the distance between the front face and the rear face to provide at least one thickness reading of the front bushing.

3. The sensing device of claim 2, wherein the at least one thickness reading comprises a first thickness reading and a second thickness reading, wherein the first thickness reading and the second thickness reading are separated by a period of use of the pump. 4 . The sensing device according to claim 3 , wherein the main body portion comprises a head portion, and the head portion comprises a communication module connected to the sensor.

5. The sensing device of claim 4, wherein the head portion is arranged to be located outside the outer surface of the housing.

6. The sensing device of claim 4 or 5, wherein the communication module transmits each of the first thickness reading and the second thickness reading from the sensor to a computing device.

7. The sensing device of claim 6, wherein the computing device compares the first thickness reading and the second thickness reading to determine a change in thickness of the front bushing over a period of use.

8. The sensing device of claim 7, wherein a user of the computing device axially adjusts the position of the front bushing relative to the main bushing according to a thickness change of the front bushing so that a distance between the front bushing and an impeller housed in the main bushing remains constant.

9. The sensing device of claim 4, wherein the body portion comprises an elongated tubular member, wherein the elongated tubular member is slidingly received within the head portion.

10. The sensing device of claim 9, wherein the first end of the elongated tubular member includes a biasing mechanism that biases the elongated tubular member toward the front bushing of the pump. The sensing device of claim 10 , wherein the biasing mechanism is a spring.

12. A sensing device according to claim 10 or 11, wherein the second end of the elongate tubular member comprises the sensor.

13. The sensing device of claim 10, wherein the main body portion is cylindrical.

14. The sensing device of claim 10, wherein the head portion further comprises at least one power source.

15. The sensing device of claim 14, wherein the at least one power source is connected to the communication module and powers the operation of the sensor.

16. The sensing device of claim 15, wherein the sensing device comprises a wired connection connecting the communication module to the sensor.

17. A sensing device according to claim 16, wherein the wired connection is arranged to enable relative movement of the elongate tubular member with respect to the head portion.

18. A sensing device as claimed in claim 16 or claim 17, wherein the wired connection is an expandable and retractable coil of insulated wire.

19. The sensing device of claim 14, wherein the at least one power source is a lithium battery.

20. The sensing device of claim 1, wherein the sensor is an ultrasonic sensor.

21. The sensing device of claim 20, wherein the ultrasonic sensor is an ultrasonic transducer.

22. The sensing device of claim 21, wherein the ultrasonic transducer is a piezoelectric transducer.

23. The sensing device of claim 1, wherein the sensing device comprises a connecting portion arranged to be connected to the housing.

24. The sensing device of claim 23, wherein the body portion is removably connected to the connecting portion such that the sensing device passes through the housing of the pump.

25. A system for detecting wear in a centrifugal slurry pump, the centrifugal slurry pump having a front bushing and a main bushing contained in a housing, wherein the front bushing is arranged to be axially adjustable relative to the main bushing, the system comprising at least one sensing device arranged to pass through the housing, wherein the at least one sensing device comprises a sensor, the sensor being biased toward contact with the front bushing and the sensor being arranged to remain biased toward and in contact with the front bushing when the front bushing is axially adjusted relative to the main bushing, thereby enabling the sensor to detect the thickness of the front bushing.

26. The system of claim 25, wherein the sensor detects a first thickness reading and a second thickness reading of the front bushing.

27. The system of claim 26, wherein the system further comprises a computing device in communication with the at least one sensing device, the computing device being arranged to receive the first thickness reading and the second thickness reading from the at least one sensing device.

28. The system of claim 27, wherein the computing device uses the first thickness reading and the second thickness reading to determine a change in thickness of the front bushing.

29. The system of claim 28, wherein a user axially adjusts the front bushing relative to the main bushing based on a change in thickness of the front bushing.

30. A method of detecting wear in a centrifugal slurry pump having a front bushing and a main bushing housed in a housing, wherein the front bushing is arranged to be axially adjustable relative to the main bushing, the method comprising the steps of: disposing at least one sensing device according to claim 1 across a surface of the housing, the at least one sensing device comprising a sensor; arranging the at least one sensing device relative to the pump such that the sensor is biased toward and in contact with the front bushing; transmitting a first thickness reading and a second thickness reading of the front bushing from the at least one sensing device to a computing device; determining a change in thickness of the front bushing due to wear using the computing device; as well as The front bushing is axially adjusted relative to the main bushing according to the thickness change of the front bushing.

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